RESUMEN
AIM: A randomized controlled clinical trial was designed to evaluate the efficacy of the photodynamic therapy (PDT) in the treatment of residual pockets of chronic periodontitis patients. MATERIAL AND METHODS: Thirty-four patients with at least four residual periodontal pockets undergoing maintenance care were included and randomly assigned to test group (PDT, n = 18) or control group (sham procedure, n = 16). The intervention was performed at baseline, 3, 6 and 12 months. Clinical parameters such as pocket probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BoP) and plaque index (PI) were measured before intervention and after 3, 6 and 12 months. Subgingival samples were obtained at baseline, and after 7 days, 3, 6 and 12 months to quantify Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia by real-time polimerase chain reaction (PCR). RESULTS: All clinical variables showed significant improvement during the study, but there was no significant difference between test and control groups. The microbiological analyses showed no differences between groups at any time during the study. CONCLUSION: Within the limits of this clinical trial and considering the laser and photosensitizer protocol used, PDT failed to demonstrate additional clinical and bacteriological benefits in residual pockets treatment.